Device and formulation

ABSTRACT

Hair grooming device comprising a head, a nebuliser, a power supply therefore and a reservoir containing a composition to be applied to the hair during use by the nebuliser, the composition comprising an emulsified composition wherein the viscosity of the emulsion is less than 8 CSt 25° C.

The present invention relates to a hair grooming device and aformulation for use therewith.

The present invention is concerned with the problem of deposition of abenefit agent, particularly high molecular weight silicone from a hairgrooming device.

Accordingly, the present invention provides a hair grooming devicecomprising a head, a nebuliser, a power supply therefore and a reservoircontaining a composition to be applied to the hair during use by thenebuliser, the composition an emulsified composition wherein theviscosity of the emulsion is less than 8 cSt 25° C.

Preferably the head is bristle or tooth-bearing, more preferably thedevice is a comb or brush. Most preferably it is a brush.

The nebuliser is selected from those known in the art. Preferably, thenebuliser comprises a gauze defined by a rigid ring, a reservoir forcontaining a composition to be nebulised and a circuit connected to thepower supply. Such a nebuliser is commercially available from Aerogen®.

Preferably, the gauze is convex with regard to the reservoir. Thisimproves the movement of the nebulised fluid on to the hair during use.

Preferably, the nebuliser is located within the head and the head alsocomprises an aperture for releasing the nebulised fluid during use on tothe hair. Preferably, the aperture is a hole or slot in the head. In apreferred embodiment there is a plurality of apertures.

Where the device is a brush it is preferred that the aperture is locatedcentrally on the brush head. More preferably, the aperture is surroundedby bristles. Where there are more than one aperture they are preferablyarranged symmetrically on the brush head to provide uniform release ofnebulised.

Where the device is a comb it is preferred that there is a plurality ofapertures located uniformly on the comb head.

Preferably, the nebuliser is located in a chamber in the device and thechamber is connected to the exterior by a channel.

Preferably, the device comprises a handle which houses the power source.Alternatively, the power source could be separate and the device poweredthrough the mains.

Benefit agents can be selected from the group consisting of fragrances,silicone oils, waxes, hydrocarbons, higher fatty acids, essential oils,hair styling polymers, colourants, hair conditioners, hair cleansers,hair growth promoters, vitamins, hair straighteners, hair growthstimulants, hair growth retardants, hair shedding inhibitors,antibacterial compounds, antifungal compounds, anti-inflammatorycompounds, anti-pruritic agents, sebum suppressants, sunscreens andmixtures thereof.

A particularly preferred benefit agent is silicone. Suitable siliconesinclude polydiorganosiloxanes, in particular polydimethylsiloxanes whichhave the CTFA designation dimethicone. Also particularly suitable foruse compositions of the invention are polydimethyl siloxanes havinghydroxyl end groups, which have the CTFA designation dimethiconol.

The viscosity of the emulsified silicone itself (not the emulsion or thefinal hair conditioning composition) is preferably at least 10,000 cSt(25° C.). The viscosity of the silicone itself is preferably at least60,000 cSt (25° C.), most preferably at least 500,000 cSt (25° C.),ideally at least 900,000 cSt (25° C.). Preferably the viscosity does notexceed 3M cSt (25° C.).

Emulsified silicones for use the invention will typically have anaverage silicone particle size (D50) in the composition of less than1000 nm, preferably less than 800 nm, more preferably less than 700 nm,ideally it ranges from 100 to 800 nm, more preferably from 150 nm to 600nm.

Suitable silicone emulsions for use in compositions of the invention areavailable from suppliers of silicones such as Dow Corning and GESilicones. The use of such pre-formed silicone emulsions is preferredfor ease of processing and control of silicone particle size. Suchpre-formed silicone emulsions will typically additionally comprise asuitable emulsifier such as an anionic or nonionic emulsifier, ormixture thereof, and may be prepared by a chemical emulsificationprocess such as emulsion polymerisation, or by mechanical emulsificationusing a high shear mixer.

Examples of suitable pre-formed silicone emulsions include emulsionsDC2-1766, DC-1785, DDC-1788, DC2-1865 and DC2-1870, all available fromDow Corning. These are all emulsions/microemulsions of dimethiconol.Preferred silicones are DC5-7051, particularly preferred are DC1788 andDC 1785.

Mixtures of any of the above described silicone emulsions may also beused.

The silicone level is preferably present at from 0.1 to 40% wt of thetotal composition, more preferably from 0.5 to 35% wt. especially from 1to 30% wt. The level of silicone that can be deposited is dependent onthe silicone used.

Compositions for use with the invention suitably comprises a carrier.Preferably, this carrier is water.

Preferably the levels of carrier in the total composition are above 60wt % of the total composition, more preferably above 70 wt %, mostpreferably above 80 wt %.

The viscosity of the final composition is preferably from 1 cSt to 8 cStat 25° C. a more preferably from 2 cSt to 7.5 cSt (25° C.), mostpreferably they have a viscosity above 3.5M cSt (25° C.). Whennebulising a silicone emulsion it is found that more silicone can bedeposited at higher composition viscosities than if a solution ofsilicone is used.

It is preferred if the products are left on hair after application andnot immediately washed off (within 10 minutes of application). Suchproducts are known as leave in compositions.

The pH of the formulation is preferably from 2.5 to 6 at 25° C. Morepreferably from 3 to 5.

Examples of suitable emulsifying agents include nonionic, cationic,anionic surfactants, or mixtures thereof. If such an emulsifying agentis used, it is preferably present at a level of from about 0.01% toabout 7.5% by weight based on total weight of the composition.

The invention will now be described with reference to the followingnon-limiting drawings in which:

FIG. 1 is a schematic section of a brush according to the invention, andFIGS. 2 a, b and c are plan views of a brush according to the invention.

In detail FIG. 1 shows a brush head 1 connected to a handle 2 whichhouses a power supply 3. The head 1 houses a nebuliser 10 which consistsof a support 5 for a gauze 7 and a reservoir 6 containing a hair carecomposition. The brush head 1 also has bristles 8 depending there fromand an aperture 9 in the head 1 for release of the nebulised hair carecomposition.

FIG. 2 shows three embodiments of apertures according to the invention.FIG. 2 a shows a brush head 1 with an aperture 9 which runs centrallydown the brush head and is surrounded on all sides by bristles 8. InFIG. 2 b there are three apertures spaced uniformly and perpendicular tothe general longitudinal axis of the brush (not shown). In FIG. 2 cthere are six apertures arranged in two lines of three diamond shapedapertures.

The following are non-limiting Examples according to the invention.

Approximately 1 g of each aqueous emulsion was nebulised into a sealedcontainer of known weight. The water was evaporated from the containerand the amount of silicone nebulised was measured by re-weighing thecontainer.

The standard error of this experiment was calculated which is equivalentto the error in the deposited value which is 0.0014 g.

Mass Mass Viscosity before after Deposited Calculated Material cSt (g)(g) (g) (g) DC-7051 3.5-4.0 19.3836 19.4788 0.0952 0.0800  10% DC-17884.5-5.0 18.8922 19.0293 0.1371 0.1400  30% DC-1785 7.0-7.5 19.015819.2516 0.2358 0.2500 50% DC-1788 40 19.0000 0 0 100% DC1785 20 19.54000 0 100%

The results of this experiment express conclusively that there is noloss of silicone transport with emulsions of the invention.

DC5-7051 (2 wt % in water) and DC200 350cSt in isododecane were appliedusing a nebuliser to dry hair. 2.5 g TA switches which were laid flat.An X-ray fluorescence sample was taken from the centre of the switch andthe level of silicone measured.

Material DC5-7051 2% DC200 350 cSt 0.5% Expected (ppm) 700 1500Delievered (ppm) 752 ±272 550 ±156 % of Expected 107% ±36 37% ±28

The above data shows that DC5-7051 emulsion at 2% exhibits betterdeposition (relative to expected value) than a solution of 0.5% DC200 inIsododecane.

1. Hair grooming device comprising a head, a nebuliser, a power supplytherefore and a reservoir containing a composition to be applied to thehair during use by the nebuliser, the composition comprising an aqueousemulsified composition wherein the viscosity of the composition is from1 cSt to 8 cSt at 25° C.
 2. Devise according to claim 1 in which theemulsified composition comprises a benefit agent.
 3. Device according toclaim 2 in which the benefit agent is a silicone.
 4. Device according toclaim 3 in which the silicone has a viscosity below 3 McSt at 25° C. 5.Device according to claim 4 in which the total level of silicone withinthe composition is 0.5 to 35 wt % of the total composition.
 6. Deviceaccording to claim 1 in which the head is a bristle or tooth-bearing. 7.Device according to claim 1 which is a brush.
 8. Device according toclaim 1 wherein the nebuliser comprises a gauze defined by a rigid ring,a reservoir for containing a composition to be nebulised and a circuitconnected to the power supply.
 9. Device according to claim 8 whereinthe gauze is convex with regard to the reservoir.
 10. Device accordingto claim 1 wherein the nebuliser is located within the head and the headalso comprises an aperture for releasing the nebulised fluid during useon to the hair.
 11. Device according to claim 1 comprising a handlewhich houses the power source.
 12. A process for depositing a hairbenefit agent onto the hair, the process comprising the following steps:i) forming an emulsified composition according to claim 1; and ii)nebulising the formulation using the apparatus described in claim 1.